[Percentile change in the beta-HCG concentration in maternal serum in disordered early pregnancy].

It is seldom possible to differentiate by means of ultrasound or clinical criteria a disturbed early pregnancy (35th-45th day). The per cent change of beta HCG concentration in the mother's serum over a certain period of time can help in such a situation. A rise of beta HCG of 30% and more means a pregnancy capable of development which--after a corresponding time--may be documented by ultrasonic prove of embryonic vitality. A lesser increase or even a decrease of the hormonal concentration points out a disturbance in early pregnancy and involves additional diagnostic steps. In a prospective study including 83 patients with symptoms of a disturbed early pregnancy it was possible to diagnose within 48 hours a positive as well as a negative correctness of the diagnosis threatened abortion, extrauterine pregnancy, incomplete or missed abortion. The per cent change of beta HCG concentration in the mother's serum shows excellent correlation with the doubling time as a biological size. The simple calculation of this parameter even allows its application in practice.